At which level is hip flexor strength described as 2/5?

At which level is hip flexor strength described as 2/5?

• A. L1
• B. L2
• C. L3
• D. L4

Answer: (A)

Hip flexion is mainly driven by the iliopsoas muscle, which is supplied by the L1–L2 nerve roots. In neuro exams that map neuromuscular level, the motor level is determined by the most caudal myotome that has at least 3/5 strength; anything weaker sits above that level. A hip flexor grade of 2/5 means the muscle can only move when gravity is eliminated, indicating substantial weakness at the level that controls hip flexion. This pattern points to involvement at the L1 level, because the L1 nerve root is at the lower end of the hip flexor’s innervation and weakness here corresponds to a 2/5 grade. Therefore, the level most consistent with this hip flexor strength is L1.

Hip flexion is mainly driven by the iliopsoas muscle, which is supplied by the L1–L2 nerve roots. In neuro exams that map neuromuscular level, the motor level is determined by the most caudal myotome that has at least 3/5 strength; anything weaker sits above that level. A hip flexor grade of 2/5 means the muscle can only move when gravity is eliminated, indicating substantial weakness at the level that controls hip flexion. This pattern points to involvement at the L1 level, because the L1 nerve root is at the lower end of the hip flexor’s innervation and weakness here corresponds to a 2/5 grade. Therefore, the level most consistent with this hip flexor strength is L1.